Filter bag



Aug. 19, 1958 C. E. MEYERHOEFER FILTER BAG Original Filed April 22, 1954 a? Z W m d, m in IW A "M 1*" tates FILTER BAG Carl E. Mcyerhoefer, Little Neck, N. Y., assignor to Lewyt Ctn'poration, Long Island City, N. Y., a corporation of New York 1 Claim. (Cl. 183-51) This invention relates to a structurally and functionally improved filter bag and especially a unit intended for use in connection with vacuum cleaners; the present invention also teaching a novel combination of filter bag structure and such vacuum cleaners.

The present application is a division of my earlier application for patent, Serial No. 424,887 on Filter Bag, filed in the U. S. Patent Oflice on April 22, 1954, now Patent No. 2,792,076.

lit is an object of the invention to furnish a unit of this type by means of which penetration of its body or wall by the high velocity impingement of dirt particles thereagainst, will be prevented.

Still another object is that of designing a filter which will be less susceptible to weakening and rupturing than heretofore and which may be economically manufactured by quantity production machinery and methods at less cost than air-pervious bags as heretofore designed.

With these and other objects in mind, reference is had to the attached sheet of drawings illustrating practical embodiments of the invention and in which:

Fig. 1 is a sectional side view taken through a portion of a vacuum cleaner assembly and showing one form of the present filter bag in association therewith;

Fig. 2 is a face view of a bag similar to that shown in Fig. l, but illustrating a slightly different construction;

Fig. 3 is a perspective View of the bag as shown in Fig. 2; and

Fig. 4 is also a perspective View illustrating a fragment of the bag body after it has been treated in the manner taught by the present invention.

Referring primarily to Fig. 1, the numeral indicates the upper casing portion of a vacuum cleaner assembly which is closed by a lid 11 conveniently mounted by a hinge (not shown). Disposed within this lid is a disktype filter 12 of air previous material. The general construction involved is substantially identical with that disclosed in United States Patent 2,716,465, dated August 30, 1955.

As taught in that patent, the upper casing portion 10 encloses an imperforate trough having an open upper face and side walls 13 spaced from the inner face of the casing walls. Due to the spacing, passages. for the flow of air are present. The base of this trough, as indicated at 14, may include an upwardly bulged or pedestal portion. Below this, a motor blower unit 15 is disposed.

As also disclosed in the prior patent, a coupling for a hose 16 is provided in association with casing portion 10. The latter mounts in line with the opening defined by this collar or coupling, a deflector shield 17, the base of which may be circular in section and the inner end of which terminates in a downwardly and inwardly opening hood. A bag of air-porous 'paper is disposed within trough 13 and includes a body 18. The latter is formed with an opening adjacent its forward end and which opening is defined by a collar 19. This collar encircles the fitting or inlet unit 17 in the manner shown in Fig. 1.

Under these circumstances, and with the motor blower "atnt unit 15 operating, dust-laden'air will be drawn through the hose coupling and deflector 17 into the interior of the bag 18. Therefore, as indicated, dust-laden particles will be directed against the inner face of the base portion or lower surface of the bag as shown in this figure. In that area, the bag is supported by the upwardly bulged part 14 of the trough, if such structure be included in the assembly. The air will distend the bag so that it substantially fills the trough with its rear end braced against the adjacent surface of the latter and its upper surface bearing against parts of the filter assembly 12.

Even if the base portion of the trough be corrugated, a minimum amount of filtered air will pass through the adjacent bag wall, although the latter be formed of airporous paper. Rather, the greatest amount of the air will move upwardly through the bag in the direction of filter 12. Thereupon, it will pass through the bag wall and the filter assembly 12 and reverse its course to flow between the inner face of casing section 10 and trough 13 toward the motor blower unit. From the latter, it

will be discharged through a suitable outlet or outlets asdisclosed in my prior patent. It is found that in the case of air-porous paper providing the surface against which the dust particles impinge upon their entrance into the bag and due to the velocity of particle movement they are forced through the paper. This will occur throughout the area indicated by the fiow lines in Fig. 1. Upon the bag being filled and removed, the adjacent base portion 14 of the trough will be covered with such particles.

By means of the present teachings, this objectionable result is avoided. More particularly and as shown in all I figures, the outer end of the bag may be defined by a square area 211, centrally of which collar 19 is mounted by having its flange glued or otherwise secured adjacent the bag opening. The side walls 21 of the bag extend from the rectangular end thereof and terminate in a base portion 22, within which there may be incorporated a suitable number of folds to provide a seal at this point. The side walls 21 include an upper part 21a and a lower part 21b. All of these parts are generally manufactured of air-pervious paper with the exception only of collar 19.

However, as shown at 23 in Fig. l, and at 24 in Figs. 2 and 3, an area of the bag body will include char acteristics different from those embraced throughout the major, air-pervious portions of the same. Specifically, these areas will be resistant to abrasion, or penetration by particles of foreign material projected against them as a consequence of the velocity of the air stream entering the bag through the collar 19. Area 23 lies within the zone of the side walls 2% and adjacent the base portion 14 of the trough. Area 24 lies within the zone of the portion 22 of the bag.

Thus, with a deflector fitting 17, as shown in Fig. l, the entering air blast will be directed against area 23. With no such fitting present, air may be discharged from the inner end of the hose directly towards the base portion 22 of the bag. In that event particles entrained within the body of the inrushing air, will strike against area 24. If a different fixture is employed in lieu of deflector 17, an area corresponding to 23, or 24 may be located as desired within side walls or base portions of the bag.

These areas may be created in desired manners. As shown in Fig. 4, a portion of the air-pervious paper has been indicated at 25. The selected area could be coated, or otherwise treated to prevent penetration thereof by particles impinging against that zone. To this end, a latex compound or a plastic such as a melamine resin known under the trademark Melamine could be employed. Other materials could obviously also be utilized.

Those materials would preferably be in liquid form. Sn;- face coating, or spraying of one or both faces of the area could be resorted to. Also, if desired, complete impregnation of that zone could occur, as indicated at 26.

In any event, after the material had dried, surface characteristics would be incorporated in the area, such that foreign particles would rebound from its face, rather than penetrating or abrading that surface. Additionally, this treatment would render the selected areas substantially impervious to the passage of air. Also, if the compound or plastic employed embody adhesive qualities, then in the event of an overlap of areas of the bag body, the layers may be secured against separation by this material. This has been indicated at 27 in Fig. 3.

It is preferred that the material employed and the treatment of the zones, be such that the flexibility of the bag will not be unduly impaired. In this manner it will be feasible to bend, roll, or otherwise dispose the unit in a manner best calculated to assure of compact packaging and storage. The desired areas could be provided at the time of the air-pervious paper being in roll form, after the bag had been blanked out, or after the unit was substantially completed. Where an overlap zone of the nature indicated at 27 was resorted to, a thickening of the bag body would result. If desired that area could be extended so as to embrace the entire zone of particle impingement, to thus doubly assure against damage to the bag during use.

Thus, among others, the several objects of the invention as specifically aforenoted are achieved. Obviously numerous changes in construction and rearrangements of the parts might be resorted to without departing from the spirit of the invention as defined by the claim.

I claim:

For use with vacuum cleaners having a compartment defined by a rigid Wall to accommodate and support a filter bag to be discarded after it has once been filled with dust and similar material, a disposable filter bag comprising a single thickness body throughout the major portion of its area, the material of said body being airpervious paper, said body having an integral upper part and lower part, an inlet opening spaced from said upper part and communicating with the interior of said body, said lower part having an integral part thereof treated with a substance so that the latter part is impervious to air and more resistant to abrasion by said dust and similar material than said air-pervious paper, said substance being a melamine resin, and said bag as defined by said body being substantially free from any air-obstructing means.

Martinet et a1. May 27, 1941 Meyerhoefer May 19, 1953 

